dopamine hypothesis

Question 1

What does the Dopamine hypothesis believe?

Answer 1

that schizophrenia is caused by a chemical imbalance in the brain linked to NT dopamine. the hypothesis suggests that the brains of schizophrenic patients produce more dopamine than those who don’t have schizophrenia.

Question 2

what does the more recent version suggest?

Answer 2

the recent version centres on the hypersensitivity of dopamine receptors for example D2 receptors, suggesting the patient with the disorder is likely to over react to the presence of the NT

Question 3

what is dopamine responsible for?

Answer 3

feeling motivation, reward and pleasure.

Question 4

how does the dopamine hypothesis explain positive symptoms?

Answer 4

hyper stimulation of D2 receptors seems to take place in the mesolimbic pathway of someone with schizophrenia - this increases the amount of dopamine in the brain and leads to positive symptoms such as hallucinations and delusions.

Question 5

how does the dopamine hypothesis explain negative symptoms?

Answer 5

hypo stimulation of D1 receptors found in the mesocortical pathway which causes a lack of dopamine causes negative symptoms such as a lack of motivation and sleep.

Question 6

how does serotonin play a role ?

Answer 6

it is possible that negative symptoms are linked to an excess of serotonin. - it has also been found that serotonin regulates dopamine

Question 7

what is the role of glutamate on schizophrenia?

Answer 7

when animals were treated with NMDA antagonist which blocks a glutamate receptor and reduces glutamate activity they showed symptoms similar to psychosis.

Question 8

what is the role of glutamate on dopamine?

Answer 8

glutamate regulates Dopamine and can increase or decrease the amount. therefore these two should be balanced to achieve normal levels of NT’s